Electrical engine-starter.



. o r I A 56mm?! )lfiaszlmore,

S. W. RUSHMORE. ELECTRICAL ENGINE STARTER. APPLICATION rum H0113, 1912.

1,079,725. Patented No v.2 5, 1913.

z I 111:;- m

93 his an its energy is directly controlled by UNITED STATES PATENTOFFICE.

SAMUEL BUSHMORE, OF PLAINFIELD, NEW JERSEY.

ELECTRICAL ENGINE-STARTER.

Specification of Letters Patent.

To all whom it ma concern:

Be it known t at I, SAMUEL W. RUsH- MORE, a citizen of theUnited States,residing at Plainfield, in the county of Union and State of New Jersey,have invented new and useful Improvements in Electrical Engine-Starters, of which the following is a speci-. fication.

This invention relates to means for starting internal combustion enginesby means of a supplemental source of power preferably an electric motor,and it includes the motor, a shiftable member such as a gear adapted toapply the powerof the supplemental motor to rotate the internal.combustion engine, together with provision for automatically throwingout the driving connection when the engine has started.

One objectof my present invention is to employ a positive driver andmeans for shifting it into and out of driving relation at the propertimes, organized and controlled so that acceleration of rotation of themotor up to the desired speed will be retarded until the positivecoupling has been efiected. In its present embodiment these objects arepresented in connection with a broader invention described and claimedinmy prior application Serial No. 722,629; filed September 27, 1912. Insaid prior application I employ a shiftable driving member such as agear, into and out of engagement at the proper time through the mediumof an electromagnetic field energized from an auxiliary source of powersuch .as a storage battery acting against mechanical opposition such asmay be afforded by a coil spring. The strength of the field iscontrolled by and in accordance with an increasing generator effect dueto increase of speed which results upon starting of the internalcombustion engine. The generator efiect thus. utilized is preferably thecounter electromotive force in the motor winding of the armature. Theresilient gear shifting effort of the spring or equivalent device isproportioned or predetermined with reference to the varying strengths ofthe field, or rather its varying gear shifting efforts, so that thedriver is automatically thrown out when the engine starts. In said priorapplication as in my present application the shifting magnet is inseries with the armature current so that the count and cause it to beshifted 'minimum jar or shock. -so arranged to open the shunt across thearmature and cut out ter electromotive force or generator effect of.

the latter, and two features of my primary invention consists inutilizing the shifting magnet as the field of the starting motor, andconnectin it in series with the armature. As app ied to such a structuremy present invention the armature by any desired means permitting fullenergization of the shifting magnet somewhat in advance of the fullenergization of the armature. Where the shifting magnet is the motorfield of a series wound motor, this may be conveniently accomplished bymeans of a controlling device adapted to first close the circuit with a.shunt across the armature so that the latter will receive much less thanthe normal current and thereby be slowly rotated while the field magnetwill receive the much eaten current necessary for efl'ecting thev iftingoperation. In actual ractice the resistance of the field is so low t ata series resistance is desirable to prevent the field acting as a shortcircuit on the battery. In this situation the positive drivingcoupling'is shifted Patented Nov. 25; 1913.

Application filed November 13, 1912. Serial No. 731,094. i

may be realized by arranging means initially under-energizing whileslowlyrotating so as to enable the I to come silently osition with thehe controller is positive engaging members and easily into'registeringthe series resistance thereby permitting maximum current to flow inseries through armature and field coils. Engagement having been thuseffec'ted, and the full torque of the motorbeing applied to the engine,the latter is drivenup to starting speed, when increasing spec and'relief of the load through starting, causes a jump in the counterelectromotive force of the motor thereby cutting'down the current, thusrendering the shifting magnet too weak to longer overbalance eresilience of the shifting spring which then op crates to disconnect thedriver. The latter continues to rotate until the supply circuit isbroken by means of the controller.

An important feature of my primary vention which I may utilize herein isthe mounting of the shifting gear directly on the armature shaft andarranging the latter forfiendwise shift in response ant eiforts. of thevarying field and the resilient spring.

.' These andother features of my invention to flhere' sult are shown inthe accompanying drawing which shows a preferred and desirableembodiment of my invention and in which the parts are designated bysimilar characters in both of the figures of the drawing.

Figure 1 shows somewhat diagrammatically the features of my invention intheir normal disengaged position when the motor is inactive and Fig. 2shows the motor in position of engagement when energized and illustratesin partialperspective a particular mechanical feature of the controllingswitch.

In the figures M indicates the starting motor consisting of an armature1 carried on a shaft 2 and having the field poles 4;4, commutator 6, andthe commutator brushes 77. A suitable frame f is indicated to supportthe pole-pieces 44- and to provide bearings 6-6 for the armature-shaft 2which as shown is elongated and provided on one end with a drivingpinion 8. This pinion 8 is adapted to engage gear teeth 10 out in therim of the engine fly wheel 12.

The engine is indicated at E and is the usual internal combustion motorof the automobile type and has the carbureter 15 and throttle valve 16.

As shown the armature is supported by the shaft 2 normally to bedisplaced longitudinally with reference to the field poles under theaction of a coiled spring 1 1 ar-' ranged between the end of the shaft 2and the end of a bearing bracket 13 attached to the supporting bracketf, The normal displaced position of the parts is shown in Fig. 1 whereit will be seen that the spring 14 has forced the armature endwise outof the field a sufficient distance to throw the pinion 8 out ofengagement with the flywheel gear 10.

Upon energizing the motor the effect is powerfully to magnetize thefield poles to exert a powerful horizontal attraction or pull on thearmature to move it into alinement with the field poles, against theinfluence of the return spring 14. While in the displaced position shownin Fig. 1 the field will not exert its maximum rotative effect upon thearmature which thus will at first be moved rapidly in a horizontaldirection but with less than maximum rotative effort owing to the thenreduced area of the effective magnetic field. The movement of thearmature into its field will carry with it the pinion 8 into drivingengagement with the gear 10, as shown in Fig. 2, thereafter the armatureand fields being in alinement, the full rotative effort is produced tostart the engine.

When the motor is driving the engine a heavy current flows through thefield coils so that: the magnet is powerfully excited. Upon theoccurrence of the first explosion in the engine cylinders, however, theflywheel and armature are rapidly accelerated.

This .increases the counter electromotive force in the armature andthereby reduces the current flow through the armature and field to sucha value that the axial magnetic pull on the armature is no longer ableto overcome the force of the end spring 1 1. The spring 14 thereforeacts to shift the armature and disengages the gears and thus the motorwill continue to spin at high speed in the disengaged position until theswitch is opened. 7

In order to insure that with gears of ordinary construction and havingblunt ends the engagement shall always be effected without shock or jarI have found it desirable to make special provision for reducing therotat-ive effort of the armature at the moment of engagement and toapply the maximum ro-tative effort only after the gears have come intoengagement. This I have accomplished by the particular device now to bedescribed.

In Fig. 1, 17 is a switch or controller box consisting preferably ofinsulating material, within which is a switch arm 18 fulcrumed at 19 andformed with an arm 20 to which is attached a tension spring 22 normallyholding the arm in the position shown. 23 is an insulating block on thearm 18 adapted to be engaged by the push rod 24: in a bearing 25 in thebox and provided at its upper end with a foot button 26 and normallyheld in elevated position as shown by a coiled spring 28. 30, 31 and 32are stationary contacts arranged to make contact successively with theswitch arm'l8 when pressure is applied to the foot button 26. Thecontact arm 18 is shown electrically connected to the commutato-r brush7 by connection 35 and the contact 30 is connected by a conductor 36with the commutator brush 7, through the resistance 37. 38 indicates aresistance interposed between the contacts 31 and 32, the latter contactbeing connected through a circuit breaker B, (to be described) to thebattery A from which the circuit is completed through connection 40 tothe motor field coil 4.

Pressure being applied to the foot button 26 the arm 18 will firstengage ,contact- 31 while still retaining cont-act with contact 30 asbest shown in Fig. 2 thus closing the circult so that a current willflow fro-m the battery A to contact 32, through resistance 38 to contact 31 there dividing, part going through the switch arm 18 andconnection 35 to brush 7, through the armature to brush 7 where it isjoined by the balance of the current which passes through the resistance37 and connection 36, the re-unitd current then passing through thefield coils 4 4, and connection 40 to the battery. In practice theconnection 36 ifnot of large cross section may serve the purpose of theresistance 37 which may in some cases be omitted.

66 her 44 formed its disengaged position interruptmg With the switch armin thisposition a will be seen that part of the current has been shuntedaround the armature so that it will contact 30 is interrupted and theentire cur-' rent will then pass through the armature and field coils,and through the resistance 38 which limits the total current to thatrequired to cause the gears without shock or jar. Upon depressing theswitch arm 18 to the end of its movement it will make contact withcontact 32 thus cutting out the resistance 38- so that the maximumcurrent will flow through the motor and the latter will exert itsmaximum efi'ort tostart theengine.

As explained above the motor automatically disengag'es from the engineafter the latter has-started to run under itsown power and has exceededa predetermined speed, and will continue to rotate at high speed in aslon arm 18 remains in contact with contact 32. 4 In order that upon thereturn movement of the switchaarm 18 it may not make contact with thecontacts 31 and 30, which would result in the flowing of a suflicientcurrent through the field coils to cause the armature to draw its pinioninto collision with the rapidly moving teeth of the flywheel gear Iprovidean inclined bridge s ring or clip 42 which will yield to allow te end of thearm 18 to pass thereunder upon the downward movement tostart the motor, but upon which the arm end will ride upon the returnmovement under the action of spring122 and thus pass freely over contact31 wit 'out making contact therewith. The switch arm for this purpose ismade sufficiently" resilient, and the clip 42 as best shown in Fig. 2 isarranged with its end resting in a notch 43 formed in the contact piece32 thus at its free and normally to be'be ow theswitch arm whereby thearm will ride thereo'ver on its return stroke and at its secured end iselevated sufliciently to permit the armto pass thereunder.

To provide against injury to the motor or gears through the wilful oraccidental operation of the above described starting switch I mayprovide means for automatically the circuit whenthe engine is operatingunder its own power. This specific means forms no portion of my resentinvention. and will be made the sub- Ject-mat-ter of a divisionalapplication. This may be operated by centrifugallyactusited means, but Iprefer to employ the detics shown, consisting of the vacuum chamby a cupelement 45"attached tobring the to slide into mesh asthe switch to thecontroller box 17 to cover an aperture 46 .in the box which is closed bya diaphragm 48. The diaphragm carries a contact 50 with a stem 51surrounded by a spring 52 adapted to press the contact into engagementwith contact point 54 through which the main circuit is'closed from thebattery.

The vacuum chamber 44 communicates with intake of the engine through thetube 55.

The spring 52 is so adjusted that the suction due to the aspiratingefl'ect of the en gine when the latter is being driven by the motor willnot be sufiicient to separate the contacts 50 and 54, but will yield andpermit the separating of the contacts when, due to the rise in speed ofthe engine when runnin under its own power, the suction is increase Itwill thus be seen that I have avoided the use of all gear shiftingmechanism and that by the simple closing of the switch the armaturepinion is automatically thrown into engagement with the gear on theengine fly wheel in the desirable manner described and after coming intofull engagement the maximum armature effort will beimparted to the wheelto cause it to revolve.

By employing the counter-electrom0tive force of the speeding motor as animportant factor for the disengagement of the motor it will be seen thatI have avoided the use of complicated mechanical devices forthatpurpose. It will readily be understoodthat this feature of my inventionmay be incororated with the armature and fields form mg the operatingmagnet, as shown, or a separate magnet may be provided having its fieldin series with the motor. In either event the operating magnet will beinfluenced by the described characteristic property of a series field tocause disengagement of the motor as a result of the decreased power ofthe magnet.

The particular arrangement described is desirable for the reasons givenbut it will be .understood that HIV device is subject to variousmodifications without departing from the spirit of the invention.

Having described my invention,

1. The combination with an engine, a starting motor with the engine, ofmeans for passing a comand means for engaging same paratively largecurrent through the field windings and less than maximum current throughthe armature until the engagement has been efiected and thereafterpasslng the full working current through the armature. v

' 2., The combination with an engine and a starting motor having thefield and arma-' ture connected in series, of means for engag: ing themotor with the engine, a shunt adapted to divert a portion of thecurrent from passing throu%hthe armature so that at the moment of elattenwill exert less than its maximum ecting engagement the Y torqueand means 'for disconnecting said shunt to cause the motor to exert itsmaximum torque for starting the engine.

3. The combination with an engine, a starting motor having a seriesWinding on its field, of means for connecting the motor to the engine,said means being actuated by the main load current passing through themotor and means for causing less than maximum current to pass throughthe motor armature, so that the armature will exert less than itsmaximum torque until the motor has been brought into engagement with theengine. 7

4. The combination with an engine, and a starting motor, of means forfirst passing the comparatively strong current through the field magnetwinding and less than maximum current through the armature andthereafter passing the full working current through the armature anddriving connections between said motor and said engine, said drivingconnections being automatically brought into operative engagement whenless than the maximum current is flowing in the armature.

5. The combination with an engine, and a starting motor having a serieswinding upon the field, of means for connecting the motor to the engine,said means being actuated by the main load current passing through themotor, and means for causing less than maximum current to pass throughthe motor armature, so that the armature will exert less than itsmaximum torque until the motor has been brought into engagement with theengine.

6. An engine, a starting electric motor, provided with means forengaging or disengaging the motor and the engine, in combination Withmeans for passing a comparatively large current through the fieldWinding and a comparatively small current through the armature untilengagement has been effected, and thereafter passing the full workingcurrent through the armature,

, and so arranged as to cause the automatic disengagement of the motorfrom the engine after the engine has reached a predetermined speed.

7.'An engine, a starting electric motor provided with means for engagingor disengaging the motor and engine, in combination with means for firstpowerfully exciting the field magnet and passing a comparatively smallcurrent through its armature until engagement'of the motor and enginehas been effected, and thereafter passing the full working currentthrough the armature and so arranged that the motor will automaticallybecome disengaged from the engine after the engine has reached a pre-,

determined speed.

8. The combination starting electric motor with an engine, a providedwith a .se-.

.the motor to the engine,

ries field winding, of means for connecting the motor to the engine,such means being actuated by the motor current, means to cause less thanthe maximum current to pass through the motor armature, so that thearmature will exert less than its maximum torque, until the motor hasbeen brought into engagement, with the engine, and means whereby thereduction in current passing through the motor after the engine hasreached a predetermined speed will cause the disengagement of the motorfrom "the engine.

9. The combination with an engine and a starting electric motor providedwith a series field winding, of means for connecting such means beingactuated by the motor current, and of means for causing less than themaximum current to pass throughthe motor armature, so that the armaturewill exert less than its maximum torque until the motor has been broughtinto engagement with the engine, and means whereby the increased counterelectromotive-force of the motor will cause the disengagement of themotor from the engine after the engine has reached a pre determinedspeed.

10. The combination with an engine, a series-wound starting motor,normally disengaged driving connections, a storage battery adapted toenergize said motor, and a controlling device adapted to close thecircuit from the battery to the motor with the armature receiving lessthan the maximum current to effect the engagement of said drivingconnections, and to thereafter deliver to the armature a maximumcurrent.

11. In combination, an internal combus= tion engine, a rotary motorarmature, a driving connection therebetween, means includ ing anelectromagnet coil adapted toshift said driving connection into drivingrelation with the engine, means for connecting said electromagnet coilfor energization independently of current fiow in the armature and forconnecting it for energization vary ing in accordance with the currentfiow through the armature to thereby effect coupling of the motor andengine and the starting of the latter.

12. In combination, an internal combustion engine, a rotary motorarmature, a

driving connection therebetween, means including an electromagnet coiland an opposing spring adapted to shift said driving connection into andout of driving relation with the engine, means for connecting saidelectromagnet coil for energization independently of current flow in thearmature,

and for connecting it in series with the armature to thereby effectcoupling and uncoupling of the driving connection.

13. In comblnation, an mternal combust on engine, a rotary motorarmature, a driving connection therebetween, means including anelectr'omagnet coil and an opposing spring adapted to shift said driving"connection into and out of driving relation with the engine, means forconnecting said electromagnet coil for energization independ ently ofcurrent flow in the armature and for connecting it in series with thearm'atnre to thereby eflz'ect coupling and un'c'ou- 10 pling of thedriving connection, and said electromagnet coil being utilized as amotor ,two' subscribing witneses.

SAMUEL W. RUSHMORE.

Witnesses:

MAUDE O. MERCER, R. T. KINGSFORD.

